…scard

Don't create discard thread when device not support realtime discard.

Signed-off-by: Fengnan Chang <changfengnan@vivo.com>
Signed-off-by: Yangtao Li <frank.li@vivo.com>

Whenever we notice some sluggish issues on our machines, we are always
curious about how well all types of I/O in the f2fs filesystem are
handled. But, it's hard to get this kind of real data. First of all,
we need to reproduce the issue while turning on the profiling tool like
blktrace, but the issue doesn't happen again easily. Second, with the
intervention of any tools, the overall timing of the issue will be
slightly changed and it sometimes makes us hard to figure it out.

So, I added F2FS_IOSTAT_IO_LATENCY config option to support printing out
IO latency statistics tracepoint events which are minimal things to
understand filesystem's I/O related behaviors. With "iostat_enable" sysfs
node on, we can get this statistics info in a periodic way and it
would cause the least overhead.

[samples]
 f2fs_ckpt-254:1-507     [003] ....  2842.439683: f2fs_iostat_latency:
dev = (254,11), iotype [peak lat.(ms)/avg lat.(ms)/count],
rd_data [136/1/801], rd_node [136/1/1704], rd_meta [4/2/4],
wr_sync_data [164/16/3331], wr_sync_node [152/3/648],
wr_sync_meta [160/2/4243], wr_async_data [24/13/15],
wr_async_node [0/0/0], wr_async_meta [0/0/0]

 f2fs_ckpt-254:1-507     [002] ....  2845.450514: f2fs_iostat_latency:
dev = (254,11), iotype [peak lat.(ms)/avg lat.(ms)/count],
rd_data [60/3/456], rd_node [60/3/1258], rd_meta [0/0/1],
wr_sync_data [120/12/2285], wr_sync_node [88/5/428],
wr_sync_meta [52/6/2990], wr_async_data [4/1/3],
wr_async_node [0/0/0], wr_async_meta [0/0/0]

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

The value of FAULT_* macros and its description in f2fs.rst became
inconsistent, fix this to keep compatibility of fault injection
interface.

Fixes: 67883ad ("f2fs: remove FAULT_ALLOC_BIO")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch supports to inject fault into f2fs_kmem_cache_alloc().

Usage:
a) echo 32768 > /sys/fs/f2fs/<dev>/inject_type or
b) mount -o fault_type=32768 <dev> <mountpoint>

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

…zero

For compressed file, after release compress blocks, don't allow write
direct, but we should allow write direct after truncate to zero.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Fengnan Chang <changfengnan@vivo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch adds f2fs_sanity_check_cluster() to support doing
sanity check on cluster of compressed file, it will be triggered
from below two paths:

- __f2fs_cluster_blocks()
- f2fs_map_blocks(F2FS_GET_BLOCK_FIEMAP)

And it can detect below three kind of cluster insanity status.

C: COMPRESS_ADDR
N: NULL_ADDR or NEW_ADDR
V: valid blkaddr
*: any value

1. [*|C|*|*]
2. [C|*|C|*]
3. [C|N|N|V]

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

s/two/three

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Do not use numbers but strings to improve readability when flag is set.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

…mpressed file

Since cluster is basic unit of compression, one cluster is compressed or
not, so we can calculate valid blocks only for first page in cluster,
the other pages just skip.

Signed-off-by: Fengnan Chang <changfengnan@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch fixes below problems of sb/cp sanity check:
- in sanity_check_raw_superi(), it missed to consider log header
blocks while cp_payload check.
- in f2fs_sanity_check_ckpt(), it missed to check nat_bits_blocks.

Cc: <stable@kernel.org>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

__add_ino_entry() will allocate slab cache even if we have already
cached ino entry in radix tree, e.g. for case of multiple devices.

Let's check radix tree first under protection of rcu lock to see
whether we need to do slab allocation, it will mitigate memory
pressure from "f2fs_ino_entry" slab cache.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Compressed inode may suffer read performance issue due to it can not
use extent cache, so I propose to add this unaligned extent support
to improve it.

Currently, it only works in readonly format f2fs image.

Unaligned extent: in one compressed cluster, physical block number
will be less than logical block number, so we add an extra physical
block length in extent info in order to indicate such extent status.

The idea is if one whole cluster blocks are contiguous physically,
once its mapping info was readed at first time, we will cache an
unaligned (or aligned) extent info entry in extent cache, it expects
that the mapping info will be hitted when rereading cluster.

Merge policy:
- Aligned extents can be merged.
- Aligned extent and unaligned extent can not be merged.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

In fs/f2fs/Kconfig, F2FS_FS_LZ4HC depends on F2FS_FS_LZ4 and F2FS_FS_LZ4
depends on F2FS_FS_COMPRESSION, so no need to make F2FS_FS_LZ4HC depends
on F2FS_FS_COMPRESSION explicitly, remove the redudant "depends on", do
the similar thing for F2FS_FS_LZORLE.

At the same time, it is better to move F2FS_FS_LZORLE next to F2FS_FS_LZO,
it looks like a little more clear when make menuconfig, the location of
"LZO-RLE compression support" is under "LZO compression support" instead
of "F2FS compression feature".

Without this patch:

F2FS compression feature
  LZO compression support
  LZ4 compression support
    LZ4HC compression support
  ZSTD compression support
  LZO-RLE compression support

With this patch:

F2FS compression feature
  LZO compression support
    LZO-RLE compression support
  LZ4 compression support
    LZ4HC compression support
  ZSTD compression support

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

I recently found a case where de->name_len is 0 in f2fs_fill_dentries()
easily reproduced, and finally set the fsck flag.

Thread A			Thread B
- f2fs_readdir
 - f2fs_read_inline_dir
  - ctx->pos = d.max
				- f2fs_add_dentry
				 - f2fs_add_inline_entry
				  - do_convert_inline_dir
				 - f2fs_add_regular_entry
- f2fs_readdir
 - f2fs_fill_dentries
  - set_sbi_flag(sbi, SBI_NEED_FSCK)

Process A opens the folder, and has been reading without closing it.
During this period, Process B created a file under the folder (occupying
multiple f2fs_dir_entry, exceeding the d.max of the inline dir). After
creation, process A uses the d.max of inline dir to read it again, and
it will read that de->name_len is 0.

And Chao pointed out that w/o inline conversion, the race condition still
can happen as below:

dir_entry1: A
dir_entry2: B
dir_entry3: C
free slot: _
ctx->pos: ^

Thread A is traversing directory,
ctx-pos moves to below position after readdir() by thread A:
AAAABBBB___
        ^

Then thread B delete dir_entry2, and create dir_entry3.

Thread A calls readdir() to lookup dirents starting from middle
of new dirent slots as below:
AAAACCCCCC_
        ^
In these scenarios, the file system is not damaged, and it's hard to
avoid it. But we can bypass tagging FSCK flag if:
a) bit_pos (:= ctx->pos % d->max) is non-zero and
b) before bit_pos moves to first valid dir_entry.

Fixes: ddf06b7 ("f2fs: fix to trigger fsck if dirent.name_len is zero")
Signed-off-by: Yangtao Li <frank.li@vivo.com>
[Chao: clean up description]
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

During f2fs_write_checkpoint(), once we failed in
f2fs_flush_nat_entries() or do_checkpoint(), metadata of filesystem
such as prefree bitmap, nat/sit version bitmap won't be recovered,
it may cause f2fs image to be inconsistent, let's just set CP error
flag to avoid further updates until we figure out a scheme to rollback
all metadatas in such condition.

Reported-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fadvise() allows the user to expand the readahead window to double with
POSIX_FADV_SEQUENTIAL, now. But, in some use cases, it is not that
sufficient and we need to meet the need in a restricted way. We can
control the multiplier value of bdi device readahead between 2 (default)
and 256 for POSIX_FADV_SEQUENTIAL advise option.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

As James Z reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=213877

[1.] One-line summary of the problem:
Mount multiple SMR block devices exceed certain number cause system non-response

[2.] Full description of the problem/report:
Created some F2FS on SMR devices (mkfs.f2fs -m), then mounted in sequence. Each device is the same Model: HGST HSH721414AL (Size 14TB).
Empirically, found that when the amount of SMR device * 1.5Gb > System RAM, the system ran out of memory and hung. No dmesg output. For example, 24 SMR Disk need 24*1.5GB = 36GB. A system with 32G RAM can only mount 21 devices, the 22nd device will be a reproducible cause of system hang.
The number of SMR devices with other FS mounted on this system does not interfere with the result above.

[3.] Keywords (i.e., modules, networking, kernel):
F2FS, SMR, Memory

[4.] Kernel information
[4.1.] Kernel version (uname -a):
Linux 5.13.4-200.fc34.x86_64 #1 SMP Tue Jul 20 20:27:29 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

[4.2.] Kernel .config file:
Default Fedora 34 with f2fs-tools-1.14.0-2.fc34.x86_64

[5.] Most recent kernel version which did not have the bug:
None

[6.] Output of Oops.. message (if applicable) with symbolic information
     resolved (see Documentation/admin-guide/oops-tracing.rst)
None

[7.] A small shell script or example program which triggers the
     problem (if possible)
mount /dev/sdX /mnt/0X

[8.] Memory consumption

With 24 * 14T SMR Block device with F2FS
free -g
              total        used        free      shared  buff/cache   available
Mem:             46          36           0           0          10          10
Swap:             0           0           0

With 3 * 14T SMR Block device with F2FS
free -g
               total        used        free      shared  buff/cache   available
Mem:               7           5           0           0           1           1
Swap:              7           0           7

The root cause is, there are three bitmaps:
- cur_valid_map
- ckpt_valid_map
- discard_map
and each of them will cost ~500MB memory, {cur, ckpt}_valid_map are
necessary, but discard_map is optional, since this bitmap will only be
useful in mountpoint that small discard is enabled.

For a blkzoned device such as SMR or ZNS devices, f2fs will only issue
discard for a section(zone) when all blocks of that section are invalid,
so, for such device, we don't need small discard functionality at all.

This patch introduces a new mountoption "discard_unit=block|segment|
section" to support issuing discard with different basic unit which is
aligned to block, segment or section, so that user can specify
"discard_unit=segment" or "discard_unit=section" to disable small
discard functionality.

Note that this mount option can not be changed by remount() due to
related metadata need to be initialized during mount().

In order to save memory, let's use "discard_unit=section" for blkzoned
device by default.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

F2FS have dirty page count control for batched sequential
write in writepages, and get the value of min_seq_blocks by
blocks_per_seg * segs_per_sec(segs_per_sec defaults to 1).
But in some scenes we set a lager section size, Min_seq_blocks
will become too large to achieve the expected effect(eg. 4thread
sequential write, the number of merge requests will be reduced).

Signed-off-by: Laibin Qiu <qiulaibin@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

[1] https://www.mail-archive.com/linux-f2fs-devel@lists.sourceforge.net/msg15126.html

As [1] reported, if lower device doesn't support write barrier, in below
case:

- write page #0; persist
- overwrite page #0
- fsync
 - write data page #0 OPU into device's cache
 - write inode page into device's cache
 - issue flush

If SPO is triggered during flush command, inode page can be persisted
before data page #0, so that after recovery, inode page can be recovered
with new physical block address of data page #0, however there may
contains dummy data in new physical block address.

Then what user will see is: after overwrite & fsync + SPO, old data in
file was corrupted, if any user do care about such case, we can suggest
user to use STRICT fsync mode, in this mode, we will force to use atomic
write sematics to keep write order in between data/node and last node,
so that it avoids potential data corruption during fsync().

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

In f2fs_remount(), return value of test_opt() is an unsigned int type
variable, however when we compare it to a bool type variable, it cause
wrong result, fix it.

Fixes: 4354994 ("f2fs: checkpoint disabling")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

We need to get sbi->s_flag to understand the current f2fs status as well.
One example is SBI_NEED_FSCK.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Turned back the remmaped sector address to the address in the partition,
when ending io, for compress cache to work properly.

Fixes: 6ce19af ("f2fs: compress: add compress_inode to cache
compressed blocks")
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Youngjin Gil <youngjin.gil@samsung.com>
Signed-off-by: Hyeong Jun Kim <hj514.kim@samsung.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

When we print out a discontinuous compression chunk, it shows like a
continuous chunk now. To show it more correctly, I've changed the way of
printing fiemap info like below. Plus, eliminated NEW_ADDR(-1) in fiemap
info, since it is not in fiemap user api manual.

Let's assume 16KB compression cluster.

<before>
   Logical          Physical         Length           Flags
0:  0000000000000000 00000002c091f000 0000000000004000 1008
1:  0000000000004000 00000002c0920000 0000000000004000 1008
  ...
9:  0000000000034000 0000000f8c623000 0000000000004000 1008
10: 0000000000038000 000000101a6eb000 0000000000004000 1008

<after>
0:  0000000000000000 00000002c091f000 0000000000004000 1008
1:  0000000000004000 00000002c0920000 0000000000004000 1008
  ...
9:  0000000000034000 0000000f8c623000 0000000000001000 1008
10: 0000000000035000 000000101a6ea000 0000000000003000 1008
11: 0000000000038000 000000101a6eb000 0000000000002000 1008
12: 000000000003a000 00000002c3544000 0000000000002000 1008

Flags
0x1000 => FIEMAP_EXTENT_MERGED
0x0008 => FIEMAP_EXTENT_ENCODED

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Tested-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

After the below patch, give cp is errored, we drop dirty node pages. This
can give NEW_ADDR to read node pages. Don't do WARN_ON() which gives
generic/475 failure.

Fixes: 28607bf ("f2fs: drop dirty node pages when cp is in error status")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

when we overwrite the whole page in cluster, we don't need read original
data before write, because after write_end(), writepages() can help to
load left data in that cluster.

Signed-off-by: Fengnan Chang <changfengnan@vivo.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This tries to fix priority inversion in the below condition resulting in
long checkpoint delay.

f2fs_get_node_info()
 - nat_tree_lock
  -> sleep to grab journal_rwsem by contention

                                     checkpoint
                                     - waiting for nat_tree_lock

In order to let checkpoint go, let's release nat_tree_lock, if there's a
journal_rwsem contention.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

We can just check f2fs_lfs_mode() directly.  The block_unaligned_IO()
check is redundant because in LFS mode, f2fs doesn't do direct I/O
writes that aren't block-aligned (due to f2fs_force_buffered_io()
returning true in this case, triggering the fallback to buffered I/O).

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Make f2fs_write_failed() take a 'struct inode' directly rather than a
'struct address_space', as this simplifies it slightly.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

xfstest generic/587 reports a deadlock issue as below:

======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc1 torvalds#69 Not tainted
------------------------------------------------------
repquota/8606 is trying to acquire lock:
ffff888022ac9320 (&sb->s_type->i_mutex_key#18){+.+.}-{3:3}, at: f2fs_quota_sync+0x207/0x300 [f2fs]

but task is already holding lock:
ffff8880084bcde8 (&sbi->quota_sem){.+.+}-{3:3}, at: f2fs_quota_sync+0x59/0x300 [f2fs]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (&sbi->quota_sem){.+.+}-{3:3}:
       __lock_acquire+0x648/0x10b0
       lock_acquire+0x128/0x470
       down_read+0x3b/0x2a0
       f2fs_quota_sync+0x59/0x300 [f2fs]
       f2fs_quota_on+0x48/0x100 [f2fs]
       do_quotactl+0x5e3/0xb30
       __x64_sys_quotactl+0x23a/0x4e0
       do_syscall_64+0x3b/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #1 (&sbi->cp_rwsem){++++}-{3:3}:
       __lock_acquire+0x648/0x10b0
       lock_acquire+0x128/0x470
       down_read+0x3b/0x2a0
       f2fs_unlink+0x353/0x670 [f2fs]
       vfs_unlink+0x1c7/0x380
       do_unlinkat+0x413/0x4b0
       __x64_sys_unlinkat+0x50/0xb0
       do_syscall_64+0x3b/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #0 (&sb->s_type->i_mutex_key#18){+.+.}-{3:3}:
       check_prev_add+0xdc/0xb30
       validate_chain+0xa67/0xb20
       __lock_acquire+0x648/0x10b0
       lock_acquire+0x128/0x470
       down_write+0x39/0xc0
       f2fs_quota_sync+0x207/0x300 [f2fs]
       do_quotactl+0xaff/0xb30
       __x64_sys_quotactl+0x23a/0x4e0
       do_syscall_64+0x3b/0x90
       entry_SYSCALL_64_after_hwframe+0x44/0xae

other info that might help us debug this:

Chain exists of:
  &sb->s_type->i_mutex_key#18 --> &sbi->cp_rwsem --> &sbi->quota_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sbi->quota_sem);
                               lock(&sbi->cp_rwsem);
                               lock(&sbi->quota_sem);
  lock(&sb->s_type->i_mutex_key#18);

 *** DEADLOCK ***

3 locks held by repquota/8606:
 #0: ffff88801efac0e0 (&type->s_umount_key#53){++++}-{3:3}, at: user_get_super+0xd9/0x190
 #1: ffff8880084bc380 (&sbi->cp_rwsem){++++}-{3:3}, at: f2fs_quota_sync+0x3e/0x300 [f2fs]
 #2: ffff8880084bcde8 (&sbi->quota_sem){.+.+}-{3:3}, at: f2fs_quota_sync+0x59/0x300 [f2fs]

stack backtrace:
CPU: 6 PID: 8606 Comm: repquota Not tainted 5.14.0-rc1 torvalds#69
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
Call Trace:
 dump_stack_lvl+0xce/0x134
 dump_stack+0x17/0x20
 print_circular_bug.isra.0.cold+0x239/0x253
 check_noncircular+0x1be/0x1f0
 check_prev_add+0xdc/0xb30
 validate_chain+0xa67/0xb20
 __lock_acquire+0x648/0x10b0
 lock_acquire+0x128/0x470
 down_write+0x39/0xc0
 f2fs_quota_sync+0x207/0x300 [f2fs]
 do_quotactl+0xaff/0xb30
 __x64_sys_quotactl+0x23a/0x4e0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f883b0b4efe

The root cause is ABBA deadlock of inode lock and cp_rwsem,
reorder locks in f2fs_quota_sync() as below to fix this issue:
- lock inode
- lock cp_rwsem
- lock quota_sem

Fixes: db6ec53 ("f2fs: add a rw_sem to cover quota flag changes")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

SBI_NEED_FSCK is an indicator that fsck.f2fs needs to be triggered, so it
is not fully critical to stop any IO writes. So, let's allow to write data
instead of reporting EIO forever given SBI_NEED_FSCK, but do keep OPU.

Fixes: 9557727 ("f2fs: drop inplace IO if fs status is abnormal")
Cc: <stable@kernel.org> # v5.13+
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This reverts commit 957fa47.

The patch "f2fs: Fix indefinite loop in f2fs_gc()" v1 and v4 are all
merged. Patch v4 is test info for patch v1. Patch v1 doesn't work and
may cause that sbi->cur_victim_sec can't be resetted to NULL_SEGNO,
which makes SSR unable to get segment of sbi->cur_victim_sec.
So it should be reverted.

The mails record:
[1] https://lore.kernel.org/linux-f2fs-devel/7288dcd4-b168-7656-d1af-7e2cafa4f720@huawei.com/T/
[2] https://lore.kernel.org/linux-f2fs-devel/20190809153653.GD93481@jaegeuk-macbookpro.roam.corp.google.com/T/

Signed-off-by: Jia Yang <jiayang5@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

When creating a file, we need to set the temperature based on
extension_list. If the empty string is a valid extension_list,
the is_extension_exist will always returns true,
which affects the separation of hot and cold.

Signed-off-by: Wang Xiaojun <wangxiaojun11@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

As 5kft reported in [1]:

set_compress_context() should set compress level into .i_compress_flag
for zstd as well as lz4hc, otherwise, zstd compressor will still use
default zstd compress level during compression, fix it.

[1] https://lore.kernel.org/linux-f2fs-devel/8e29f52b-6b0d-45ec-9520-e63eb254287a@www.fastmail.com/T/#u

Fixes: 3fde13f ("f2fs: compress: support compress level")
Reported-by: 5kft <5kft@5kft.org>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Added gc_reclaimed_segments and gc_segment_mode sysfs nodes.
1) "gc_reclaimed_segments" shows how many segments have been
reclaimed by GC during a specific GC mode.
2) "gc_segment_mode" is used to control for which gc mode
the "gc_reclaimed_segments" node shows.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>